1. Field of the Invention
The present invention relates to a biaxial hinge device suitably applied to cellular telephone devices, PHS (Personal Handyphone System) telephone devices, PDA (Personal Digital Assistant) devices, portable game devices, notebook computers, and so forth, which have a hinge portion enabling opening/closing of a housing, for example, and to a portable terminal device.
More specifically, the present invention relates to a biaxial hinge device and to a portable terminal device which enable the number of springs used to be reduced to one while including two rotational shafts of a first rotational shaft and second rotational shaft, thereby realizing reduction in size by an amount equivalent to that of the reduced springs, and which enable space for wiring a cable to be omitted by employing a first barrel-shaped shaft member making up a first rotational shaft, and a second barrel-shaped shaft member making up a second rotational shaft, and performing wiring of a cable or the like through each hole portion of the first shaft member and second shaft member, thereby realizing reduction in size.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2005-198062 (pp. 8-9, FIG. 5) discloses in a clamshell type cellular telephone device having three folding functions which are a function of opening/closing in the longitudinal direction of an upper housing, a function of opening/closing in the lateral direction, and a function of folding in a state of the front and back of the upper housing having been inverted.
This clamshell type cellular telephone device has a hinge portion configured separately of a first hinge portion and a second hinge portion. The first hinge portion has a first rotational shaft rotatably supporting the first hinge portion itself as to a lower housing, and a second rotational shaft rotatably supporting the second hinge portion as to the first hinge portion, with the first rotational shaft and the second rotational shaft disposed in a mutually orthogonal arrangement. The second hinge portion is provided with a third rotational shaft which rotationally supports the upper housing as to the second hinge portion, such that the second rotational shaft is disposed orthogonal to the second rotational shaft. Accordingly, the upper housing can be rotated on each of the rotational shaft directions of the first rotational shaft, second rotational shaft, and third rotational shaft.